Tornado
Tornado is a spinning column of air that reaches from a storm cloud down to the ground.
When you drain a bathtub, the water spirals down into the drain in a tight, spinning funnel shape. The funnel is wide at the top and narrow at the bottom where it meets the drain. A tornado works the same way but upside down. The wide spinning top connects to a storm cloud, and the narrow tip reaches down to touch the ground.
Explaining tornado by grade level
When you flip the soda bottle, the water spins fast. It makes a shape like a cone. That spin pulls air up through the middle. Real wind can spin the same way in a storm.
Projects that explore tornado
A tornado is a spinning column of air — a vortex — that pulls into a funnel shape as it reaches from cloud to ground. When you swirl two connected bottles, water drains in that same spinning motion. Add food coloring or plastic confetti and the vortex becomes visible, letting you study how the spinning funnel behaves as it forms.
The spinning column of air in a tornado can vary in size depending on the energy available to sustain the vortex. In a Perspex chamber with a bathroom exhaust fan pulling air upward, dry ice placed in heated water produces a wider spinning column than dry ice in cooler water. At 30 degrees Celsius the vortex reaches its largest diameter. Drop the temperature to 10 degrees and almost no visible tornado appears — showing that thermal energy directly controls how large the spinning column grows.